Scratch that! Took the car onto a very smooth bit of road, back windows down and the pops at 3k overrun are far meatier than my old
290. The exhaust on the Copra sounds so much better. All the worry is unwarranted.
To get the soundaktor out, open the bonet and there's a piece of rectangular foam on the left. Pull that up (it's just pop clip fittings) and under it you'll see a black pop clip fitting. Pull that out with plyers and you can then Jimmy up the black plastic it was holding down, soundaktor is right below that. It'll have a grey release tab on it, just pull that apart. Push all the foam back into place and done. Doesn't take more than a minute all in all.